A preliminary investigation by the National Transportation Safety Board (NTSB) revealed that an American Airlines flight caught fire soon after taking off from Denver International Airport in March due to several parts being installed incorrectly. The Dallas-bound aircraft had one part installed in the wrong direction and fuel leaking from another fitting.
The crew noticed issues with the right engine shortly after takeoff, but landed safely without incident. However, passengers and crew members soon detected fire and smoke upon arrival at a gate, prompting an emergency evacuation.
Examination of the plane’s damage revealed substantial harm to the right wing and fuselage near the engine area, including heat/smoke/burn indications, fuel leaks, and fractured fan blades. Another part controlling airflow through the turbine’s compressor was found to be incorrectly fastened, causing a leak.
172 passengers and six crew members were on board at the time of the incident. Although 12 passengers sustained minor injuries, all others escaped safely without major harm.
Source: https://www.foxnews.com/us/american-airlines-plane-caught-fire-had-engine-parts-installed-incorrectly-ntsb-finds